A pneumatic tire for use on an icy/snowy road surface is often buried in snow up to buttress portions thereof each situated between a tread end and a sidewall portion when the tire runs on a road covered by deep snow. The tire is required to exhibit desired running performances such as traction performance even in such a state as described above. In view of this, the conventional pneumatic tire for use on an icy/snowy road surface is provided with buttress portions having configurations as shown in PTL 1, for example.